This build is made mostly as an attempt to make the Mystic Theurge's 2 sets of spell slots actually work in combination instead of being two seperate sets of spells a level and a half lower than they should be. This is accomplished using the Theologian Cleric Archetype, which allows domain spells (in this case fireball from the fire domain) to be prepared in non-domain slots and have metamagic applied to them.
at level 20, this build will look something like: Theologian 3, Admixture Wizard 6 (for intense spells and the ability to change elements) Tattooed Orc/Gold Dragon Sorcerer 1, Mystic Theurge 10.
Comparison to a normal admixture wizardEdit
This build has both advantage and disadvantages over your standard blaster wizard. the biggest advantage is that you will be casting almost twice as many fireballs in one day than most blaster casters, and your lack of high level spell slots hardly matters thanks to spell mastery. the disadvantage is the easier spell DCs and the fact that you now have 2 casting stats to worry about. also, because you only get 6 wizard levels your intense spells bonus caps at +3. but the most fun thing about this build is the theurge capstone. once a day, cast 2 fireballs as a standard action, and leave your swift for a third, quickened one... and with admixture, you can make one of them a fireball, one of them an iceball, one of them a lightning ball, and yell out "TRI ATTACK" as you fell your foes in a triple ball of destruction.
Level progression, feats, and ability scoresEdit
this build is mostly theorycraft, but if you want to actually play one, remember to go straight for the prestige class. most blaster casters take the sorcerer level first, but this would delay you too much. this means you will suck a bit at early levels. be a sasmaran if you have the ultimate race guide - otherwise be a human. take your wizard levels first, then cleric, then all ten of mystic theurge. after that take your first sorcerer level before finishing off with wizard again. for the most part, your feat progression will be the same as that of the Admixture Blaster, but remember that you get no bonus feats.
If you are a Sasmaran, this is what your ability scores would look like on 20-point buy.
Dex:7 (I hate it to be this low, but this is a bit of a MAD character)
Int: 18 (16+2)
Wis: 18 (16+2)
Cha:11 your Dex sucks, so get the Reactionary trait in addition to the Magical Lineage trait. take the Greensting Scorpion and Improved Initiative - you will need it!